The Whispering Pines Thagard Lake dam replacement project will replace the existing dam, which consists of four segments that were constructed between the years 1900 and 1964. Based on the North Carolina Dam Safety quantitative guidelines, Thagard Dam is classified as High Hazard.
Thagard dam is the largest of the 10 lakes/ponds/dams owned by the Village of Whispering Pines, impounding more than 103 million gallons of water.
Over the last few years, several deficiencies, repairs, and investigations have been noted/conducted on the dam. The most concerning ones are seepage along the interface of the dam and rock outcrops, cracks and leakage throughout the primary and secondary concrete spillways, and concerns of internal deterioration of the concrete (such as Alkali-Silica Reaction, ASR), said the Village on its website.
Given the age of the dam and the high costs of further investigating the current condition, design, and implementing repairs, the Village has opted to pursue replacement of the dam. This project is the highest priority for the Village due to the size and condition of the existing dam and the high hazard risks associated with a potential failure.
The estimated cost for the construction of a new dam is highly dependent on the subsurface condition (i.e., underlying rock formation) and could range from $8,000,000 to $12,000,000 depending on the required foundation treatment, said the Village.
Click here for the dam improvement plan.
Photo of Thagard Lake by Sandhills Sentinel photographer Wendy Hodges.
Contributed.
